Control for operating elevator systems



Jan. 5, 1954 H, C, CRANE CONTROL FOR OPERATING ELEVATOR SYSTEMS FiledMay 6, 1952 INVNYOR,

HARQLD c. CQANG, E2 5% RTTY Patented Jan. 5, 1954 UNITED STATES PATENTYOFFICE Harold C. Crane, Toronto, OntariogCanada Application May 6,195.2, Serial`No.286,227

1 '22 Claims.

This invention relates to a control for an elevator system serving aplurality of floors of a building.

In known elevator systems, during periods of heavy traina such as theevening departure traffic peak, service is apt to beslow. Variouscontrols have been devised to improve service during these periods. Forexample, some controls measure the time from which a signal is made, andi1" a predetermined time elapses and the signal remains unanswered thatsignal is answered in priority to others which were subsequently made.Other-controls assign a zone o iloors and a quota of signals to eachcar. In the known systems, however, service may be slow due to the factthat each car ofthe elevator system makes a large number of stops,frequently picking up only one passenger at a stop.

It is an object of the invention to improve service in an elevatorsystem when signals for a car are made from several floors.

lt is anotherobject of the invention to reduce the number ofstops madeby a car vof an elevator system and to increase the average number ofpassengers pick-ed up at each stop. Y

...In the embodimentV of the invention hereinafter described in greaterdetail, the car stopping means of an elevator system are operated in thesequence in which signals are made from the various floors, but when apredetermined number of means Vis rendered inoperative when a car isThus, only a prestopped at its associated floor. determined number rofear stopping means is in operation at one time, and the car stoppingmeans that ar-e in operation are those for the oors from which theearliest signals were made. Later signals are held in abeyance on signalregisters which are coupled together to register the signals in theorder in which they are made, and thesignal registers operate the carstopping means for their associated floors only as 'prior'operated carstopping means are rendered inoperative. Since only a predeterminednumber of car stopping means is in operation at one time, the number ofstops made by a car can be held to, say, two or three for each trip in agiven direction, and since the earliest made signals are answered iirstthe number oi passengers picked up at each stop is greater on theaverage than in systems having conventional controls. in modern elevatorsystems, it takes about siX seconds for deceleration,

door time, and subsequent acceleration, so that if three or four stopsare eliminated the round trip time is'reduced by 20 to 25 seconds, orby, say, 25%. Furthermore, since in accordance with this inventon'thenumber of Acar stopping means in operation at a given time is reduced, acar will, on the average, reverse Vat a lower door than it does When allthe car stopping means for which signals have been made are in operationat the same time. In the result, since a car makes more trips per hourthe system can handle a higher peak rate '0f traic, or can handle thesame traflic with the average number of passengers in a car reducedabout 35 Also in the `embodiment' hereinafter described, a plurality of-iloors of a building are provided with signal` registers responsive tosignals from the signalling means for their associated iioors toregister the signals,` and the signal registers are coupled 'together toregister the signals in a predetermined sequence and to operate the carstopping means for their associated floors in a predetermined sequence,but only a predetermined number of car stopping means can be operated atone time. vFor registering the signals each vsignal register preferablyhas an arm movable to a plurality of positions, and the means couplingthe signal registers together controls the positions of the arms, thuscontrolling the sequenee in which the signals are recorded on theregisters and controllingthe sequence in which the car stopping meansare operated.

A further feature of the invention is the provision of means operable toreverse an ascending car inresponse'to the time of ascent of a carand/or in response tothe number of signals that have been made from thesignalling means.` A still furtherl feature is the provision of meansresponsive to the number 'of signals made to vary the interval betweencars;

l The single ligure of the drawings illustrates one embodiment of theinvention. The embodiment illustrated employs. a stepping switch foreach floor above; the ground iloor of the building,

f each stepping switch constituting a signal register. -F'or the purposeof this description it will be assumed that the building has ten doorsabove the ground floor, but-for simplicity the connections for only asingle upper iioor are shown, the connections for the other upper floorsbeing similar. Additional connections common to all floors are alsoshown. Connections for only the down button vare shown, vsince normallyit is not necessary to give priority vto up signals at the variousiloors.

The stepping switch for each upper floor is of conventional constructionand is illustrated diagrammatically. The switch has four groups or"contacts, known in the stepping switch art as levels,y designated in thedrawings as level A, level B, level C and level D. Each level: has adummy contact, hereinafter called the normal contact, and, for abuilding having ten upper floors, each level has ten additionalcontacts. The additional contacts for level A are designated AI, A2 AIO,those for level B are designated B, B2 BIO, and so on. The normalcontacts are designated AN, BN, CN and DN. For each level, the steppingswitch has a' f wiper, the wipers being designated WA for levelv A, WBfor level B, WC for levelC, and WD for level D. The wipers are mountedfor synchronous rotation (counterclockwise, as illustrated) on a commonshaft I2, and each wiper has three arms 120 apart. In the drawings, thewipers are'shown in what will be called the normal position, whichV istaken up when-no down signal is registered for the associated oor; inthisposition, an arm of each wiper rests on anormal contact. ,If,arwipeiy is rotated i209, the, arm which i'ormerlyrested onu the normalAcontact moves overall the contacts of `its level, coming to rest beyondthe-first contact, and.r another arm of the wiper comes to rest onthenormal contact. As will be Iseen below, ,if the first down signal inthebuilding is Inade athsay, the i'ifth floor, the stepping switchforthe fifth iioor moves to what will be `called thefijst position, withan arm of wiper WA at contact AI, onarm oi wiper vWB at contact B I,andso Yon.v If the down signal for the `iifth iioor. remains`unanswered, andk agdown ysignal is next made at the seventh floor, thestepping switch forptheseventh floor moves to the. second position, withan arm of its ywiper WA atits contact lA`2, an arm of .its wiper WB atits contact B2, and vso ,.on.` r ASimilarly if unanswered down signalsareY made ,at all ten floors, the stepping switchfor theiioor at which adown signal Vwas rlastumade ytakes up the tenth position with its wipersonuits contacts AIG, BIO, ,CIG andv DIIl.Y Thus, the order in which thelsignals are made ,at thevarious floors isreilected inthe positionstaken by the stepping switches associated with the floorsto register thesignals, and suitable connectionsare f.

made ateach position to give the first registered signals thehighestpriority.- Only thel two (.for example) longest registeredsignals are Apassed on to car stopping`v means `which stopqthe next carsat thefloors ,from which-.the signalscame, and the.remainder. of theYsignals f are `held qinsuspense in the order in which they werev regis-.tered. As soon as the signal fonl one -iloor is answered, the steppingVv switch for. that-'oorgreturns to the normal positionto awaita-furtherdownsignaLand Vthe stepping switches which had occupied higher'numberedfpositions move one step to lower numbered posi-tions. Thus-ifXsignals are, waitingtobe answered, the stepping switch for the iooriorwhich lthelast signalwasregistered always occupies vthe positact I4re-closes. On there-closing of the contact I4, a ratchet (not shown)rotates the wipers counterclockwise one step to the next position. Ifvoltage is still being supplied across the solenoid I3 and the contactI4, the operation repeats and the switch takes another step.

The solenoid I3 and contact I4 are connected between a negative supplyline I5 and a single pole double throw switch IS. The switch I6 isoperated by a cam I'I mounted on the shaft I2, and the cam is rotatablesynchronously with the wipers WA, WB, WC and WD. When the wipers are inthe normal position, the cam I'I holds the "switch I6 in what will becalled its normal position, in which it is connected through the downbuttonV I8 at the associated floor to a positive supply line I9. Whenthe down button I8 is pressed, the solenoid I3 is energized and thestepping switch takes a step, moving the wipers to the tenth positioncontacts AIO, BIO, CIOand DIO Vand rotating the Icam I'l, permitting theswitch I6 to move to its other position, where a normally open resetcontact 20 breaks the circuit from the line I9 via the switch I'to thesolenoid` I3. .i

Let it Ybehas'sumed that the down button at only the iifthfloor` hasbeen pressed, so that the steppingswitches for all other iioors areinthe normal position. As described in the preceding paragraph, inresponse to asignal from the down button at the fifth floor, thestepping switch for the Vfiithfloor moves to the tenth position. ,Thecontacts A2 to AID are connected tovthepositive line I9 throughconnections AA and through normally closed relay contacts RI to R0respectively. The connectionsvAA connect the contacts A2,` to AIG foreach upper ,floor to the contacts A2 to AI 0 respectively for everyother upper floor so thatv the A contacts for all upper floors ,areinthe same condition of energization or Vcle-energization. The wiper WAis permanently connected by a lead A2l to the interrupter contact I4, onthesame side of the contact YIll asjthe switch I6. When the wiper WA ison the contact AIG, a circuitis completed from the positive line I9through the relay contactRS,v the contact AIU, the wiper WA, thelead 2|the contactull andthe solenoid I3 to thefnegative line I5. Thus, thestepping switch moves another step to the ninth position. AAt thel ninthposition, since the vrelay Contact R8 is closed, the switch takesanother step to the eight position, and soon v,until it reaches theiirst position. The contact AI-isgnotfconnected to the line I9, so thatat this position voltage is no longer supplied tothe solenoid 'I3 andthe stepping switch tions BB and through the coils of blocking Vrelays-RI to- R5 respectivelyv which' Acontrolthe contacts 'Ri to R9.' :Theconnections BB connectthe contacts` BI to BQ of each" stepping switch tothe contactsBI to BS respectively'of the steppingswitches -for all"other oors. With the stepping vswitch for-the fth fioor in the first`position, a circuit is completed from the line i9 through the coil-ofblocking relay Ri' to the contactz BI for the'iifth floor, and thencethrough the wiper WB for the iifthv iioor and the lead 22 to the lineI5.- gized andopens thecontact RI, thus disconnecting Vthe contactsAZ-fOreVery-fioor from the line; I8. Ii thenext down button pushed isbn.

Therelay RI is thereby'enersay, the seventh iioor, the stepping switchYfor the seventh'oor-will proceed only as farias the second position,sincethe contacts A2 zfor every floor are not energized. The wipervWBfor the seventh floor takes up the second position, on contact B2,energizing the blocking relay R2 and opening the relay contact R2, thusde-energizing the contacts .A3 sothat thenext stepping switch ,to beoperated by. pressing a down button will stop at the third position, andso on. In general, if any position Xis oc-Y cupied by a stepping switch,the next .stepping switch to operate in response toa signal from thedown button for its associatedfloorwill take up the position X-f-l, sothat the signals from the various floors are registered in the sequencein which they are made. The positions to which the wipers move arecontrolled by the blocking relays which are common to all the steppingswitches and thus couplev them together. As will now be described withreference to level C, the Vblocking relays, by preventing successivelyoperated stepping switches from overtaking one another, limitthe numberof car stopping means in operation at one time yto a predeterminednumber, so that the earliest signals to be registered are answered rstand the'answering'of subsequent signals is delayed.

The wiper WC i is permanently connected through a resistor 23 vand arelay 24 to the line I5. The relayl 24 is a conventional floor relaywhich, when energized,`causes the next descending car to stop at the:door with which the relay is associated. The contacts CI and C2 arepermanently connected to the `line I9 -through a connection CC andavlead 25, so that when Athe wiper WC is in either the rst-or' thesecond position the' floor relay-24 is energized. Thecontacts C4 toCIinclusive are connected together by means of a shunt 21', andtheshuntZ'I is connected to the line 'I9 througha Aconnection CC and anormally closed relay contact RC. The contact C3 is connected through aconnection CCy to a single pole vdouble throw switch '.28 which, in oneposition; connects the contact C3 through the lead 25 to the line I9,vand in its other position connects the contact C3 through the relaycontact RC to the line I9. The connections CC link together lthecorresponding C contacts of all the stepping switches.

The relay contact 'RCy opens as soon as the irstv and second positionsare occupied. This is achieved by connecting a call relay RC in serieswith two normally open relay contacts RIa and REa across the linesvI5^and I9; The relayV yAssume for the moment that the contacts C3 ofthestepping switchesare connected by the switch 2B to the relay contact RC.With thel rst and second positions of the stepping switches occupied,and the` relay contact RC open, when a third signal comes in, say on theninth door, the ninth` floor stepping switch moves to the thirdposition; butsince the contacts C3 are not connected Ato the line I 9'the oor relay for thelninth'llioor, does not become; energies"1Sinnen;ricerca.. Seres eze.

held in suspense at the fourth, fifth,Y etc. positions.

The purpose of the relay RC is tofmaintain service ifV oneof thestepping switches sticks. If one of the stepping switches sticks, itprevents any subsequently operating Stepping switch from overtaking it,and therefore there will beunoccupied high priority positions. TherelayRC ensuresthatif ythe rst two positions are not occupied, the floorrelays .will be picked up by stepping switches occupying higher numberedpositions so that all car stoppingl means for which signals have beenmade are operated concurrently until theV first two positions are takenup. Priority is thereby lost, but at least service is maintained. v

Let it be assumed that the down buttons have been pressed at the' fth,seventh, ninth .and second oors, in that order, so that the steppingswitches for thesefloors occupy the rst, second, third and fourthpositions, respectively. Further let it be assumed that the, switch 28is connected to the contact' RC, which of course will be open. With theswitch 28 connected to the vcontact RC, the only floor relays 24 `thatare energizedV are those for the fth and 'seventh floors. A descendingcar will be stopped, first, at the seventh iioor. When the car-'stops atthe seventh floor it closes the reset contact 2G for the seventh floorso that the seventhfloor solenoid I3 is energized through Vthe switch I6and the seventh door stepping switch moves counterclockwise to thenormal position; at the normal position, the cam I1 returns the switchI6 to the position shown in the drawings, thus stopping the steppingswitch until the seventh floor down button I8 is pressedv again. `Byreturning the seventh floor stepping switch to 'its normal position, thereset contact 20unco'uple's the seventh iloor relay 24 from theAstepping switch and renders that floor relay inoperative.

Due to the movement of the wiper WB 'of the seventh floor steppingswitch from the second position, the relay R2 is de-energized, and theninth and second floor stepping switches can move to the second andthird positions, respectively. Meanwhile, the car descends vto thefthfioor. Thus, only the nrst two or three signals are answered by the nrstdescending car; the number of signals given highest priority can bevaried by changing the position of the switch 28. Further, it will beseen thatfa's the earliest operatedV stepping switches are returned totheir normal positions, subsequently operated stepping switches advance,in the sequence in which signals were registered on them, to thepositions where they are coupled to the floor relays for theirassociated oors.

The contacts DI and D2 are conneted'to the line I9 through a connectionDD'and a nas'he'r 29.

` The contacts D4 to DI 0 inclusive are connected to a shunt 30, and theshunt -30 is connected to the line I9 through a lconnection DD and a.Alead '3L The contact D3 is connected through a connection DD to asingle pole' double throw switch 32 which can be connected either to theasher 29'01" the Q without-flashing because theyareonnecteditdireadytow-,heine :stnrough tneiead 3|: The signal indicator lights 33 arearranged on an indicator panel on the ground floor, where they informthe starter and the public as to which signals have the highestpriority'. As in'most elevator systems, a manual switch 34 isv providedon the starters control panel on the ground oor, and this switch isconnected in series Vwith a high lcall reversal relay 35 across thelines l and i9. Whenthe relay 35 is energized, it reverses eachascending car at the floor for which the highest signal has been made,whether-the signal was made by means of a hall button or by means of abutton in the car. The starter may close the switch 3d during 'thoseperiods of the day when the cars are most in demand, so that the carsneed not travel to the top lfloor before reversing.

According to this invention, means are provided tocut the high callreversal relay in and out automatically as traiiic conditions vary. Anormally open relay contactRZb is connected across Athe switch 34; thecontact R221 closes when theblockingrelay R2 is energiZed,thuscausingthe-lhigh call reversal .relay 35 to pick upas soon-as two down.signalsare` registeredQ` Also connected across the switch 34 is acircuitconsisting'ofnorf-`r mally open relay,` cont'actvRibl infseries? with abank of .normallyopen ltiming relay-contacts TI, VT2 andTS, thelattercontacts'beingscon` nected inlparallel.-5y The contact- Rib closes whenthe blocking. relay-,Rl rvis energized, e. 'when one down signal'rsregistered.- Fachy timingrelay contactl iscontrolledKV by `a timingvrelay (not showmf associated -withfwone `of thel cars; vit 'is hereassumedrthat-there are three cars and there-v fore three timing relays.Each `timing relay is set -torclose itstimingfrelay 'contact if theassociatedcarfis still travelling up after,"say,40 seconds from-the-timeV.it-left the ground -1"1oor.` there is one down signal registered, andany-'car takes more thanf40 seconds on 'the up 'trir`i,"the4 high callreversal relay 35 is energized: Also con# nected across'the switchfll isa banko'f normally" openrtimingrelay `contacts TTlyTTZ `'and'T'IL iconnected Yinparallel.- A`'These contacts 'are closedv by another groupvof timing relays (not shown)' set to-operate if any' caris stilltravelling lupV after, say, 50 seconds from 'the time 4it left'theground floor; A Y These last relays are 'usefulA during the morningrush'hour whenall thetraic is'inthe updirection:4 v f-lnlmany elevatorsystems, a' variable speed timer motoras provided to 'malntainadesired=1n' j Whicha signal may be madewhen it is* desired tervalbetween the ,timesd that successive "cars leave-the ground floor.` Apotentiometeris pro-V vided by means of which the starter can'vary"thevspeed "of -thetimer motor, Vthu'sva'ry'ingl theim terv'albetween-cars5-fv A."-i'ccording-to this inventionfthe "time" interval'betweenV cars may be" automatically varied to'pr'e-'- vent wasteof'tim'eat'the'ground'iioor during' periods' of heavy down' traiiic.`Cor'inettecl' across the lines l 5 and lI Sis a potentiometer33anfdftlf1e shunt Y'eldwinding 37 or a` direct current timer motor 38.Onesideo the arrn'a'tndre'f the motor 38fis connected to the line l5,and the other side is connected'to a`network 391i Dependingnpon down'trac conditions, the networkfcnnects heY armature 'todiierent'points'orfthe pdterit'iometer 36, thus varying the voltagelsupplied ktothe arma-rfA ture of the motorl'wherebythe motorvaries'hthev time intervalbetweeh cars". The neijivg'rorkr 39 conn-Msists `of a 'pair' ofiioifnally ``pen cntacts R2 c and Thus, ifv

RSC connected in'series between the armature of the motor and the lineI5, a normally closed contact RZd connected to the armature and to avariable tap 36a, on the potentiometer 3B, and a normally closed contact'R311 connected to a point between the contacts R20 and RSC and to avariable tap 3th on the potentiometer. The contacts RZC and R30 closewhen the second and third positions respectively are occupied bystepping switches, and the contacts R2d and R311 open when the secondand third positions respectively are occupied by stepping switches.Thus, when no down signals are registered, or when only one down signalis registered, the armature of the motor 38 is connected through the'contact RZd to the tap 36a, a relatively low voltage is applied to thearmature, and the motor rotates at a speed corresponding to the desiredtime interval between cars for this traiiic condition. The position ofthe tap 36a can of course be varied as desired. When two down signalsare registered, the contact Rd opens and the Contact R20 closes,connectingthearmature to the tap- 36h, thus supplying ahigher voltageVto the armature and speeding upithe motor to reduce the time intervalbetweencars. .-Similarlyy whenv three down signalsY are registered, thecontact-ESCI opensand the contactV R3cfcloses, giving full voltagevtothelarmature and a minimum'time interval between cars.

. For convenience in servicing and for economy in wiring, most lof theapparatusfthat has `been described is located in thepenthouse of thebuild` ing: eachvupper floor merely has a push-buttonv I8,"and,.theindicating lights 33- and the switch- 34 areeat the groundfloor. f Theinvention has been described as appliedl to an elevator systemhavingiloor relays Zlybuti it will be obvious to those skilled in theart that the oorrelaysamay be eliminated andthe stopping of the carsmaybe controlled directly by the stepping switches.Y The form :of theinvention herewith shown and described is merelyl a preferred example,and many changes `inrappara-Y tus and arrangement may be made `withoutde parting-from the scope of the invention as de-v fined in thesubjoined claims. f 'Y ,What I- claim as my` inventionris:.

l. Ar control for an velevator system` serving a plurality ofupperiloors of a building, compris.

ing car stopping means associated` with each said iioor and operable tostop a car of the elevator system `at the associated floor, the-carstopping means being renderedinoperative upon stoppingV acar, signallingmeans vfor each saidoor from to operate ,the car stopping meansyassociatedV with Athat oor, signal registeringmeans responw` sive tosignals made from :the signalling means. toregisterfthe signals-in thesequence in which they are made, lthe signal registering-means op-Aeratingthe car stopping means for which signals have been made in thesequence in which theY signals are registered, and blocking means for;delaying the` operation of further car stopping meansV until the-numberof car stopping means'. already in operation falls below a predeterminedto operate the car stopping means associated with that floor, signalregistering means responsive to signals made from the signalling meansto register the signals in the vsequence in which they are made, thesignal registering means operating the car stopping means for whichsignals have been made in the sequence in which the signals areregistered, the signal registering means including means for operatingconcurrently all car stopping means for which signals are made until thenumber of car stopping means in operation reaches a predeterminednumber, and blocking means for delaying the operation by the signalregistering means of further car stopping means until the number of carstopping means already in operation falls below the predeterminednumber.

3. A control for an elevator system serving a plurality of upper oors ofa building, comprising car stopping means associated with each saidiloor and operable to stop a car of the elevator system at theassociated floor, the car stopping means being rendered inoperative uponstopping a car, signalling means for each said floor from which a signalmay be made when it is desired to operate the car stopping meansassociated with that floor, a signal register associated with each saidfloor and interposed between the signalling means for that floor and thecar stopping means for that floor, the signal registers being responsiveto signals made from the signalling means for the floors with which thesignal registers are associated to register the signals, the signalregisters being coupled together to register the signals in the sequencein which they are made, and the signal registers operating the carstopping means for the iloors with which the signal registers areassociated as prior operated car stopping means are renderedinoperative, the signal registers operating the car stopping means inthe sequence in which the signals are registered.

4. A control for an elevator system servingia plurality of upper oors ofa building, comprising car stopping means associated with each saidfloor and operable to stop a car of the elevator system at theassociated oor, signalling means for each said floor from Which a signalmay be made when it is desired to operate the car stopping meansassociated with that iloor, a signal register for each said 'iioorinterposed between the signalling means for that floor and the carstopping means for that floor, each signal register being responsive toa vsignal from the signalling means for its floor to register the saidsignal, the signal registers being coupled together to register thesignals in the sequence in'which the signals are made, the signalregisters operating the car stopping means for their oors in'thesequence in which the signals are registered, and means blockingoperation of the car stopping means to limit the number of car stoppingmeans in operation at any time to a predetermined number.

5. A control for an elevator system serving a plurality of upper floorsof a building, comprising car stopping means associated with each saidiioor and operable to stop a car of the elevator system at theassociated floor, thel car stopping means being rendered inoperativeupon stopping a car, signalling means for each said oor from which asignal may be made when it is desired to operate the car stopping meansassociated with that floor, a signal register for each said floorresponsive to a signal from the signalling means for that iioor toregister the said signal, the sigvnal registers being coupled togetherto register tive.

6. A control for an elevator system serving a plurality of'upper iloorsof a building, comprising car stopping means associated with each saiddoor and operable to stop a car of the elevator system at the associatedoor, signalling means for each floor from which a signal may be madewhen it is desired to operate the car stopping means associated withthat floor, a signal register associated with each said iioor andresponsive to a signal from the signalling means for the associatedfloor to register the said signal, means for coupling a predeterminednumber of signal registers to the car stopping means for theirassociated floors, the predetermined number of signal registersoperating the car stopping means to whichthey are coupled, means foruncoupling the signal registers up to the predetermined number may becoupled to the car stopping means for their associated floorsy and meanscoupling the signal registers together for controlling the sequence inwhich the signal registers are coupled to the car stopping means.

7. A control for an elevator system serving a plurality of upper floorsof a building, comprising car stopping means associated with each saidoor and operable to stop a car of the elevator system at the associatedfloor, signalling means for each said floor from which a signal may bemade when it is desired to operate the car stopping means associatedWith that oor, a signal register associated with each said floor andhaving an arm movable in response to a signal from the signalling meansfor the associated iioor to register said signal, means for coupling apredetermined number of signal registers to the oar stopping means fortheir associated floors, the predetermined number of signal registersoperating the car stopping means to which they are coupled, means foruncoupling the signal registers from the car stopping means as cars arestopped at the associated floors so that further signal registers up tothe predetermined number may be coupled to the car stopping means fortheir associated floors and means coupling the signal registers togetherand responsive to movement of the arms for controlling the sequence inwhich the signal registers are coupled to the car stopping means.

8.' A control for an elevatorlsystem serving a plurality of upper iioorsof a building, comprising oar stopping means associated with each saidiloor andy operable to stop a car of the elevator system at thevassociated iioor, signalling means for each said 'oor from which asignal may be made when it is desired to operate the car stopping meansassociated with that floor, a signal register associated with each saidiloor operable in response to a signal from the signalling means for theassociated iloor and having an arm movable-to a plurality of positions,the arm being movable to one of said positions in response to saidsignal to register said signal, means coupling the signal registerstogether, the coupling means controlling the positions to which the armsoi. successively operated signal registers move in response to signalsfrom the signalling means for their associated floor whereby the signalsare registered in a predetermined sequence, and means for couplingsignal registers to the car stopping means for their associated floors,the signal registers operating the car stopping means in thepredetermined sequence.

9. A control for an elevator systemserving a plurality of upper floorsof a building, comprising car stopping means associated with each saiddoor and operable to stop a car of the elevator system at the associatedoor, signalling means for each said floor from which a signal may bemade when it is desired to operate the car stopping means associatedwith that floor, a signal register associated with each said flooroperable in response to a signal from the signalling means for theassociated floor and having an arm movable to a plurality of positions,which positions correspond to similar positions of the other signalregisters, the arm of each register being movable to one of itspositions in response to said signal from the signalling means for theassociated floor to register said signal, means coupling the signalregisters together, the coupling means controlling the positions towhich the arms of successively operated signal registers move wherebythe earliest operated signal registers take up predetermined positions,means for coupling the signal registers taking up the predeterminedpositions to the car stopping means for their associated floors inpriority to other signal registers, and means for operating concurrentlyall car stopping means for which signals are made until saidpredetermined positions are all taken up.

10. A control for an elevator system serving a plurality of upper iioorsof a building, comprising car stopping means associated with each saiddoor and operable to stop a car of the elevator system at the associatedfloor, signalling means vfor each said oor from which a signal may bemade when it is desired to stop a car at that floor, a signal registerfor each said iioor operable in response to a signal from thesignalling` means for the associated oor, each signal register having anarm movable to a plurality of numbered positions in succession, whichpositions correspond to similarly numbered positions of the other signalregisters, the arm being movable to one of its positions in response tosaid signal from the signalling means for the associated floor toregister said signal, means coupling the signal registers together, thecoupling means controlling the movement of the arms of successivelyoperated signal registers whereby the arms take up consecutive numberedpositions to register the signals in a predetermined sequence, thesignal registers operating the car stopping means for their associatedfloors in the sequence in which the signals are registered, and thecoupling means including means blocking operation of the car stoppingmeans to limit the number of car stopping means in operation at any timeto a predetermined number.

ll. A control for an elevator system serving a plurality of upper iioorsof a building, comprising car stopping means associated with each saidioor and operable to stop a car of the elevator system at the associatedoor, signalling means for each said oor from which a signal may be madewhen it is desired to stop a car at that floor, a stepping switchassociated with each said floor and operable in response to a signalfrom the signalling means for the associated door, each stepping switchhaving stepping means movable from a normal position to a plurality `ofnumbered positions in succession, the numbered positions of eachstepping switch corresponding to similarly numbered positions of theother stepping switches, the stepping means being movable to one of thenumbered positions in response to said signal from the signalling meansfor the associated floor to register said signal, means coupling thestepping switches together, the coupling means including blocking meansassociated with the numbered positions and actuated by the steppingmeans of a switch occupying a numbered position to prevent the steppingmeans of the next operated stepping switch from moving to that positionuntil the position is unoccupied, whereby the stepping means of thestepping switches take up consecutive numbered positions in the order inwhich they are operated, means for coupling a predetermined number ofstepping switches whose stepping means occupy predetermined numberedpositions to the car stopping means for their associated iloors, thepredetermined number of stepping switches operating the car stoppingmeans to which they are coupled, means for returning the stepping meansof each of the predetermined number of stepping switches from thepredetermined position occupied by the stepping switch to its normalposition when a car is stopped at the associated floor whereby thestepping switch is uncoupled from the associated car stopping means,thus rendering inoperative the car stopping means and the blocking meansassociated with the predetermined position so that the stepping means ofanother stepping switch can move to the predetermined position.

l2. A control for an elevator system serving a plurality of upper iioorsof a building, comprising car stopping means associated with each saidiioor and operable to stop a car of the elevator system at theassociated floor, signalling means for each said floor from which anelectrical signal may be made when it is desired to stop a car at thatoor, a source of electrical energy, a stepping switch associated witheach said door, each stepping switch having electrically operable motivemechanism and a pair of arms movable by the motive mechanism insynchronism, each arm having a plurality of positions, the positions ofone arm comprising, in sequence, a normal position, a plurality ofcontacts normally energized from the source of electrical energy, saidcontacts forming normally energized positions of the one arm, and anon-energized position of the one arm, and the positions of the otherarm comprising, in sequence, a normal position and a plurality ofsubsequent positions to which said other arm is movable in synchronismwith said one arm, the positions of each stepping switch correspondingto similar positions of the other stepping switches, the motivemechanism of each stepping switch being actuated by an electrical signalfrom the signalling means for the associated floor to move the one armof the step-ping switch from its normal position to a normally energizedposition, the contact of said position when energized connecting the onearm and the motive mechanism in series with the source of electricalenergy whereby the motive mechanism is actuated to move the one arm tothe next normally energized position, and so on until the one armreaches a non-energized vpositionat which the motive mechanism is notactuated, the one arm taking up saidnon-energized position, and theother arm, having moved in synchrcnism with said one arm, taking up one-of its subsequent positions, means coupling the stepping switchestogether, the coupling means including blocking means actuated by saidother arm at said subsequent position to de-energize'for all thestepping switches the contact of the normally energized position priorto the position taken up bysaid one arm whereby said prior positionbecomes the non-energized position taken up by the next .operatedstepping switch,v so that the subsequently operated stepping switchestake up consecutive normally energized positions in kthe order in whichthe stepping switches. are operated, means for coupling a predeterminednumber of stepping switches taking up predetermined positions to the carstepping means for their associated floors, the predetermined number ofstepping switches operating the car stopping means to which they arecoupled, means for returning each of the predetermined number ofstepping switches from vthe predetermined position occupied by thestepping switch to its normal position when a car is stopped atthe-associated floor whereby each said stepping` switch is uncoupledfrom the associated car stopping means thus rendering inoperative thecar stopping means and rendering inoperative the blocking means whichde-energized the position prior to said predetermined position, wherebya stepping switch positioned at said prior position moves to saidpredetermined position.

13. A control for an elevator system serving a plurality of upper floorsof a building, comprising car stopping means associated with each saidiioor and operable to stop a descending car of the elevator system atthe associated floor, the car stopping means being rendered inoperativeupon stopping a descending car, signalling means for each said floorfrom which a signal may be made when it is desired to operate the carstopping means associated with that iloor, signal registering meansresponsive to signals made from the signalling means to register thesignals in the sequence in which they are made, the signal registeringmeans operating the car stopping means for which signals have been madein the sequence in which the signals are registered, blocking means fordelaying the operation of further car stopping means until the number ofcar stopping means already in operation falls below a predeterminednumber, means operable automatically to reverse an ascending car at a.desired iloor of the building, and means for operating said automaticreversing means and including timing means responsive to the time ofascent of the car and means responsive to the number of signalsregistered.

14. A control for an elevator system serving a plurality of upper floorsof a building, comprising car stopping means associated with each saidfloor and operable to stop a car of the elevator system at theassociated oor, the car stopping means being rendered inoperative uponstopping a car, signalling means for each said floor from which a signalmay be made when it is desired to operate the car stopping meansassociated with that iloor, signal registering means responsive tosignals made from the signalling means to register the signals in thesequence in which they are made, the signal registering means operatingthe car stopping means for which signals have been made inthe 'sequencein which the signals'are registered, blocking means for delaying the`operation of further car stopping means untilthe number of car stoppingmeans already in operation falls below a predetermined number, avariableV timer for controllingthe interval between cars of the elevatorsystem,` and means responsive to the number ofsignals registered to varythe timer and thus vary the interval between cars.

15.V A control for an elevator system servingv a plurality of upperiloors of a building, comprising car stoppingmeans associated with eachsaid floor and operable to stop a .car of the elevator system at theassociated floor, the car stopping means beingA rendered inoperativeupon stopping a car, signalling means for each saidfloor. from whichafsignalmaybe made when it is desired tooperate the car stopping meansassociated with that iloor, signal registering. means responsive tosignals made from .the signalling means to register the signals in thesequence in which they are made,.the.signal registering means operatingthe car stopping means for whichsignals have been made in the sequence'in which the signals are registered, blocking means for delaying theop@ eration of further car stopping means until-the number ofcarstoppi-ng means already in operation falls below a predeterminednumber, a signal light associated with each said floor, means foroperating the signal lights when signals are made from the signallingmeans for their associated floors, and means for flashing selectedsignal lights.

16. A control for an elevator system serving a plurality of upper oorsof a building, comprising signalling means for each said iloor fromwhich a signal may be made when it is desired to stop a car of theelevator system at that floor, signal registering means responsive tosignals made from the signalling means to register the signals in thesequence in which they are made, and means for stopping a car of theelevator system in response to the longest registered signals on thesignal registering means.

17. A control for an elevator system serving a plurality of upper floorsof a building, comprising signalling means for each said iloor fromwhich a signal may be made when it is desired to stop a car of theelevator system at that oor, signal registering means responsive tosignals made from the signalling means to register the signals in thesequence in which they are made, and means for stopping a car of theelevator system in response to the longest registered signals on thesignal registering means to answer said longest registered signals, andmeans for removing the signals from the signal registering means whenthey have been answered.

18. A control for an elevator system serving a plurality of upper oorsof a building, comprising signalling means for each said floor fromwhich a signal may be made when it is desired to stop a car of theelevator system at that floor, signal registering means responsive tosignals made from the signalling means to register the signals in thesequence in which they are made, and means for stopping a car of theelevator system in response to the longest registered signals on thesignal registering means, a signal light associated with each saidiioor, means for operating the signal lights when signals are made fromthe signalling means for their associated Iioors, and means for flashingthe lights that have been in operation the longest.

19. `A control for an elevator `systeml serving a plurality of upperfloors of a building, comprising signalling means for each said floorfrom which a signal may be made when it is desired to stop a car of theelevator system at that floor, signal registering means Vresponsive tosignals made from the signalling means to register the signals in thesequence in which they are made, and means for stopping a car of theelevator system in response to the longest registered signals on thesignal registering means, a signal light associated with each saidfloor, and means for ashing the signal lights for the oors for whichsignals have been longest registered.

20. A control for an elevator system serving a plurality of upper oorsof a building, comprising signalling means for each said floor fromwhich a signal may be made when it is desired to stop a car of theelevator system at that floor, a signal light associated with each saidoor, means for operating the signal lights when signals are made fromthe signalling means for their associated floors, and means for flashingthe lights that have been in operation the longest.

21. A control for an elevator system servinga plurality of upper floorsof a building, comprising signalling means for each said floor fromwhich a signal may be made when it is desired to stop a descending carof theA elevator system at that oor, means operable automatically toreverse an ascending car at a desired floor of the building, and meansfor operating said automatic reversing means and including timing meansresponsive to the time of ascent of a car and means responsive to thenumber of signals made from said oors.

22. A control for an elevator system serving a plurality of upper floorsof a building, comprising signalling means for each said floor fromwhich a signal may be made when it is desired to stop a car of theelevator system at that floor, a Variable timer for controlling theinterval between cars of the elevator system, and means responsive tothe number of signals made from said floors to vary the timer and thusvary the interval between cars. Y v HAROLD C. CRANE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,039,568 Tamsitt May 5, 1936 2,067,378 Chubb Jan. 12, 19372,568,418 Suozzo Sept. 18, 1951 2,581,245 Eames Jan. 1, 1952 2,589,292Santini Mar. 18, 1952

